1. Field of the Invention
The present invention relates to stator for a rotating machine and a rotating machine using the same.
2. Description of Related Art
Forms of winding of a stator include concentrated winding where a wire is wound in a concentrated manner for each tooth of a magnetic pole to prepare a coil and distributed winding where a wire is wound over a plurality of slots, with coils of different phases or same phases being superposed at coil ends. The concentrated winding can be made with a reduced coil end as compared with the distributed winding, and is effective for downsizing and making the rotating machine highly effective. On the other hand, in the case of the distributed winding, the distribution of magnetic field at the inner periphery of the stator can be made close to sine waves and a higher output than that of the concentrated winding can be obtained with reduced noises. Also, there is a method of using a copper wire having a square cross-section for a coil to increase the space factor of the coil in the slots of the stator and increase a density of current as means for achieving higher output from a rotating machine common to both types of winding.
Japanese Patent No. 3651491 discloses a technology according to which the coil ends of concentrated winding cores are inserted through connection holes of a printed board or a connection plate constituted by a plurality of copper plates, coil grooves that extends in an axial direction are provided corresponding to the positions of the connection holes, and the coil ends are connected to the respective connection holes by fusing peripheral walls of the coil grooves.
Japanese Laid-open Patent Publication No. 2006-204029 discloses a connection structure constituted by coil ends inserted through holes of a resin-molded bus bar (conductor) and the coil ends are connected to the bus bar via separate parts such as tubes and connectors. According to the technology disclosed in Japanese Laid-open Patent Publication No. 2006-204029, coil ends of U-, V-, and W-phases in order are repeatedly arranged in the peripheral direction. The lengths in the axial direction of the both ends of the coil are the same, so that radial positions of the coil ends to be inserted through the bus bar are the same.
According to Japanese Laid-open Patent Publication No. 2006-246594, a connection structure is adopted in which insulation layers and bus bars (conductor) are laminated and coil ends are inserted through holes provided in respective insulation layers and bus bars, with predetermined coil ends being connected to predetermined bus bars, respectively.
Each of the technologies of the above-mentioned patent references is adapted to be compliant to low voltage operations.